1. Field of the Invention
The present invention relates to a method and a circuit for controlling a mobile terminal. More particularly, the present invention relates to a method and a circuit for controlling a reception path of a multi-standby terminal.
2. Description of the Related Art
With the rapid development in mobile terminal technology, mobile terminals providing various functions, such as a voice and message communication function, a video communication function, an electronic organizer function, and an internet function, have become popular. Furthermore, multi-standby terminals that can simultaneously communicate with two or more wireless communication networks are being developed. Such a multi-standby terminal can simultaneously communicate not only between different wireless communication networks (for example, CDMA-GSM) but also within two identical wireless communication networks (for example, GSM-GSM).
Generally in a mobile communication terminal, a filter may be installed between an antenna and a Radio Frequency (RF) receiver to maintain reception sensitivity by attenuating a transmission power to reduce its influence on a reception path.
However, in a multi-standby terminal having two or more communication modules, if a first communication module is in a transmission state and a second communication module is in a reception state, a single filter cannot efficiently attenuate a transmission power that is influencing a reception path. That is, the reception sensitivity of the second communication module may be reduced because transmission power of the first communication module influences a reception path of the second communication module, and thereby electrically saturates a low-noise amplifier or generates oscillation. To address this problem, a plurality of filters may be installed in series in the second communication module. Although installation of the plurality of filters in series may help attenuation of the transmission power, a loss of a reception signal is induced due to the filters. This may lead to reduction of the reception sensitivity of the second communication module when the first communication module is not in a transmission state. Therefore, development of a circuit for controlling a reception path of a multi-standby terminal is required such that the reception path of the second communication module can be controlled according to the transmission state of the first communication module.